Lock attachment



S..Z|OBRO.

LOCK ATTACHMENT. APPLICATION FILED MAY 23. 1919.

Patented Dec. 16,1919.

Sfazziey Zzob m UNITED STATES STANLEY ZIOBRO, 0F WESTPORT, CONNECTICUT.

' LocK ATTACHMENT.

Application filed May 23, 1919.

To all whom it may concern:

Be it known that I, STANLEY ZIOBRO, a citizen of Pola'nd, residing at Westport, county of Fairfield, and State of Connecticut, have invented certain newand useful Improvements in Look Attachments, of which the following is a specification.

This invention has as its special object the provision of means whereby a lock bolt when extended is prevented from being retracted by the ordinary use of a key.

A further object is to provide means whereby the checking attachment may be so manipulated as to become operative or inoperative at will.

These and other like objects are attained by the novel construction and combination of parts hereinafter described, and shown in the accompanying drawings, forming a material part of this disclosure and in which- Figure 1 is a face view showing a fragment of a door having a lock set therein and indicating the application of the invention.

Fig. 2 is a fragmentary side elevational view of the same.

Fig. 3 is a similar view thereof, parts being shown in another position, and

Fig. 1 is a perspective view showing one of the main elements of the lock attachment.

Referring to the drawings, the numeral 10 indicates an ordinary form of door, containing a lock mechanism 11, including a face plate 12, through which extends a latch bolt 13, actuated by a knob or handle 14, and a lock bolt 15, ordinarily operated by a key 16, the same being entered through the opening 17, the entire construction of the lock and operative parts being immaterial for the purpose of the present invention.

In carrying out the invention, a small notch 18 is formed transversely in the lower side of the lock bolt 15, at some distance from the extreme outer end, as indicated best in Fig. 1.

A thin metallic lever 20 is pivoted to the face plate 12 of the look by a screw 21, one of the ends of thelever having a part 22 adapted to engage within the notch 18, when the lock bolt is in an outward position, the lever being constructed of flexible material and so positioned as to prevent the retraction of the lock bolt when the element 22 is engaged therein.

Formed with the opposite end of the lever Specification of Letters Patent.

Patented Dec. 16, 1919.

Serial No. 299,171.

20 is an arm 23, extending at a right angle to the main portion of the lever and terminating in a knob 2 1, by which it may be actuated so as to turn the lever upon the screw 21, and in order to hold the lever when in a disengaged position, a notch 25 is formed in its lower edge, engageable with which is another lever 26, pivoted upon a pin 27, fixed in the side of the lock and provided with an extending actuated knob 28, by which the second lever may be so manipulated as to engage within the notch 25, holding the lever 20 in an inoperative position. The lever 26 is held within notch 25 by the engagement of lever 26 with a pin in the door. As shown in Fig. 3 a pin 30 holds the lever 26 under the arms of lever 23.

It will be obvious however, that upon swinging the lever 26, so as to engage with the stop pin 29, due to the weighted end 24 of the arm 23, the lever 20 will be caused to assume a vertical position and engage with the lock bolt when extended, at which time the operation of a key is prevented,

the key having insufficient strength to either shear the element 22 or dislocate the pivot screw 21.

Thus the attachment may be used as a further security to an ordinary door lock, V efiectually preventing the entrance of unauthorized people, even if provided with a key to the lock. Having thus described my invention what I claim as new and desire to secure by Letters Patent, is

In a lock attachment, the combination with a key operated lock having an extensible lock bolt provided with a transverse notch, of a lever pivoted so that a portion thereof may enter the mentioned notch when the bolt is in an extended position, a weighted angular arm formed with said lever, said arm having an open slot, a second lever pivoted on the side of said lock, and an actuating knob for operating said second lever so as to engage within the men'- tioned slot whereby the first lever may be held in an inoperative position, and means for holding said lever within said slot, said arm being normally adapted to cause the first lever to assume a vertical operative position.

In testimony whereof I have afiixed my signature.

STANLEY ZIOBRO. 

